Portable holder for dental tools or the like



Nov. 4, 1969 H. LOGE I 3,475,817

PORTABLE HOLDER FOR DENTAL TOOLS OR THE LIKE Filed May 24, 1967 n IlllHHIHllLll I 7 /a. U A 3 5 72a /2 54.

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INVENTOR #4; A 042- j 1 wwssm 44a ATTORNEY United States Patent Int. Cl.A61c 1/10, 1/14 US Cl. 3226 9 Claims ABSTRACT OF THE DISCLOSURECross-reference to related application 7 A transmission which can beutilized to drive the clutch in the holder of my invention is disclosed,for example, in the copending application Ser. No. 630,602 filed by Logeet a1. and now Patent No. 3,436,981 issued April 8, 1969, and assignedto the same assignee.

Background of the invention The present invention relates to surgical orlike outfits in general, and more particularly to improvements inportable holders or hand pieces which can be utilized in power-drivensurgical outfits to releasably hold and transmit torque to drilling,boring, polishing, grinding or like surgical tools. It is already knownto provide a dental outfit with a holder or hand piece whichaccommodates a chuck serving to releasably retain the shaft or stem of asurgical tool and to drive the tool when it receives torque from theoutput member of the associated drive. The means for disengaging thechuck from the tool shaft normally comprises a thumb piece whichresembles a lever and is adjacent to the peripheral surface of thehousing which accommodates the chuck. Asa rule, the user of the holderapplies to the lever some thumb pressure in order to disengage thechuck. Such application of pressure can occur accidentally, for example,when the dentist drills the tooth of a patient, and can cause seriousinjuries as well as embarrassment to the dentist. Furthermore, the leveris likely to interfere with proper grasping of the holder in actual use.

Accordingly, it is 'an important object of the present invention toprovide a novel and improved holder or hand piece for dental or liketools, and to construct and assemble the holder in such a Way that thedanger of accidental release of the tool is eliminated in a very simpleand unobvious way.

Another object of the invention is to provide a portable holder whichcan be more readily grasped by hand than heretofore known holders andwherein the tool can be disengaged from the chuck only when the outfitwhich embodies the holder is not in actual use.

A further object of the invention is to provide a portable holder of theabove outlined character which can bereadily incorporated in or combinedwith presently known surgical outfits or like instruments.

An additional object of the invention is to provide ice a novel housingor casing for a portable holder of the above outlined type. v

A concomitant object of the instant invention is to provide a holder orhandpiece which is safer, simpler and less expensive than presentlyknown holders.

An ancillary object of the invention is to provide a novel mode ofdisengaging the chuck in the holder of a surgical or like outfit.

Summary of the invention One feature of the present invention resides inthe provision of a portable holder or hand piece for dental or liketools. The holder comprises a chuck having an actuating member which ismovable between operative and inoperative or idle positions in which thechuck is respectively in a condition to engage and release a tool, and ahousing which preferably resembles a sleeve surrounding the chuck andhas at least one opening positioned with reference to the actuatingmember in such a way that the user can introduce therethrough theworking end of an implement (for example, the tip of a small lever orpry) by means of which the actuating member can be moved between itsoperative and inoperative positions. The arrangement is preferably suchthat the chuck comprises biasing means for permanently urging theactuating member to operative position and that the working end of theimplement is used to move the actuating member to inoperative position.

The housing preferably comprises a tubular main body portion consistingof one or more sections and a plate-like insert which is fitted into acutout of the main body portion and is provided with the aforementionedopening or openings. The wall thickness of the plate-like insert is lessthan the wall thickness of the remainder of the housing, at least in theregion immediately surrounding the opening or openings, so that theworking end of the implement can be fulcrumed on the edges of the insertduring movement of the actuating member to inoperative position.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved holder itself, however, both as to its construction and itsmode of operation, together with additional features and advantagesthereof, will be best understood upon perusal of the following detaileddescription of certain specific embodiments with reference to theaccompanying drawing.

Brief description of the drawing The single figure of the drawing is apartly elevational and partly axial sectional view of a holder whichembodies my invention, the implement being indicated by broken lines.

Description of the preferred embodiments Referring to the drawing indetail, there is shown a holder or hand piece which serves to releasablyretain and to rotate a surgical tool, for example, a dental drill 5.This drill has a smooth-surfaced cylindrical shaft or stem 5a whichcarries at its forward end a drilling element Sb. The housing 1 of theholder resembles an elongated sleeve and comprises a main body portioncomposed of a series of interconnected tubular sections 1a, 1b, 1c thelatter of which has an open front end 1d to permit insertion orwithdrawal of the stem 5a. The housing 1 further includes a bearingsleeve 1h which is received in the sections 1a-1c and engages the outerrace of an antifriction bearing Is for the hollow cylindrical forwardend portion of an output shaft 2 which serves to transmit torque to thestem 5a through the intermediary of a chuck 3. This chuck comprises aring-shaped actuating member 6 which is remote from the front end 1d andis movable,

within limits, in the axial direction of the output shaft 2 between anoperative or rear end position and an inoperative or forward endposition in which the chuck 3 is respectively in a condition forengagement with and disengagement from the stern 5a. The actuatingmember 6 surrounds the output shaft 2 and is axially movably coupledthereto by a diametral pin 7 extending through elongated axiallyparallel slots 8 of the output shaft. Thus, the actuating member 6shares all rotary movements of the output shaft 2 but is movable axiallybetween its operative and inoperative positions. The pin 7 furtherconnects the actuating member 6 with a cylindrical chuck sleeve 4 whichis axially movably received in the output shaft 2 and whose front end isprovided with a set of radially movable wedge-like chuck elements ordogs 4:: cooperating with a complementary chuck element 11 which isreceived in the foremost section 1c forwardly of the bearing 1e and isconnected with the front end 2a of the output shaft 2. The chuck 3 alsocomprises biasing means in the form of a prestressed helical expansionspring 9 which operates between an annular flange 10 of the output shaft2 and the front end face of the actuating member 6 to bias the latter tooperative position. When the spring 9 is free to expand, it maintainsthe actuating member 6 in the illustrated position whereby the pin 7enters the rear ends of the slots 8 and pulls the chuck sleeve 4rearwardly so that the dogs 4a are forced into the tapering spacebetween the smooth peripheral surface of the stem 5a and the chuckelement 11. Since the sleeve 4 shares rotary movements of the outputshaft 2, its dogs 4a compel the stern 5a to rotate with the output shaftand to rotate the drilling element 5b. The dogs 4a tend to move radiallyand away from the stem 5 so that the stem is released if the actuatingmember 6 is caused to move forwardly (i.e., downwardly, as viewed in thedrawing) in order to shift the sleeve 4 and dogs 4a in a directiontoward the front end In. Such movement of the actuating member 6 can beeffected by resorting to an implement 16 (shown by broken lines) whoseworking end 16 can be introduced through an opening 12 provided in aplate-like insert 14 which is affixed to the rearmost housing section Inby one or more screws 13 or analogous fasteners. The insert 14 is fittedinto a suitable cutout or depression which is machined into the section1a and its opening 12 registers with a larger opening or cutout in thesection 1a. The opening 12 is provided in the region of the rear end 3aof the chuck 3. The insert 14 preferably consists of suitablewear-resistant synthetic plastic or metallic mateiral and the opening 12is preferably of polygonal outline. It was found that a rectangularopening is particularly suited for my purposes and that such rectangularopening may have a length of about 1.5 mm. and a width of about 3 mm.,as seen in the axial and circumferential direction of the housing 1. Theinternal surface of the insert 14 is preefrably provided with adepression 15 so that the wall thickness of the insert around theopening 12 is less than the wall thickness of the remainder of theinsert and housing 1. This insert 14 can be said to constitute aknife-edge bearing for the working end 16a.

In utilizing the implement 16 (which can resemble a small L-shaped leveror pry), the user must first terminate the drilling action so thatdetachment of the stern 5a from the chuck 3 cannot cause injury to thepatient. The working end 16a is introduced through the opening 12 insuch a way that it can pivot on an edge bounding the opening and thatits tip bears against the rear end face of the actuating member 6. Theoperator then simply pivots the implement 16 in a clockwise direction,as viewed in the drawing, to move the actuating member 6 downwardlywhereby the pin 7 moves the chuck sleeve 4 axially and causes the dogs4:: to move radially and away from the perihperal surface of the stem5a. The tool 5 is ready to be withdrawn or leaves the sleeve 4 bygravity. Reinsertion of the tool 5 can be carried out by reversing thejust described procedure, i.e., the working end 16a is caused to movethe sleeve 4 downwardly and the stern 5a is introduced into the chucksleeve through the front end 10.. The user then removes the working end16a from the opening 12 and the spring 9 automatically returns theactuating member 6 to operative position.

The rear end portion 215 of the output shaft 2 is rotatable in anantifriction bearing 17 'provided in the rear section 1a and has anannulus of teeth 2c which can be engaged by teeth on an intermediateshaft provided in the casing of a transmission serving to drive theoutput shaft 2. A suitable transmission is disclosed in theaforementioned copending application of Loge et al. The rear end of thesection 1a is provided with a bayonet slot 1 which can receive a bayonetpin on the casing of the transmission. The exterior of the section 1a ismilled or knurled, as at lg, to provide a better gripping surface forthe users fingers. The manner in which the output shaft 2 receivesmotion from the transmission forms no part' of the present invention.

Of course, the housing 1 can be provided with two or more openings. Thedrawing shows a second opening 12a which is indicated by broken linesand is disposed diametrically opposite the opening 12. The oepning 12ais machined directly into the material of the section 1a but it isequally possible to employ a second plate'like insert. The internalsurface of the section 1a may be provided with a depression 15a so thatits wall thickness is reduced in the region immediately surrounding theopening 12a. The number of openings can be increased to three or more,as long as they do not unduly weaken the housing. One opening willnormally suffice and is more desirable because the interior of thehousing 1 is less likely to accumulate dust or other foreign matter.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

I claim:

1. A portable holder for dental and like tools comprising, incombination, an elongated rotary chuck means having a front end and arear end and being provided at said front end with a gripping portionfor receiving a tool inserted therein; rotary abutment means surroundingsaid gripping portion, said rotary chuck means being movable in axialdirection with respect to said rotary abutment means between anoperative and a releasing position for respectively gripping andreleasing a tool received in said gripping portion; a housingsurrounding said rotary chuck means and said rotary abutment means andhaving at least one lateral opening rearwardly of said rear end of saidchuck means; an actuating member in said housing connected to said rearend of said chuck means for movement in axial direction therewith, saidactuating member extending into the region of said open ing; biasingmeans cooperating with said actuating member for yieldably maintainingthe same in a position in which said chuck means connected thereto is insaid operative position; and an implement insertable in and removablefrom said opening for engaging said actuating member and for moving thelatter together with said chuck means against the force of said biasingmeans to said releasing position.

2. A holder as defined in claim 1, wherein said housing resembles asleeve having an open end remote from said opening to permit insertionof a portion of a tool.

3. A holder as defined in claim 1, wherein said housing comprises a mainbody portion and a plate-like insert aflixed to said main body portion,said opening being provided in said insert.

4. A holder as defined in claim 1, wherein said housing comprisesportions of greater and lesser Wall thickness, said opening beingprovided in the portion of lesser wall thickness.

5. A holder as defined in claim 1, wherein said implement is a lever,and wherein one edge of said opening provides an abutment for said leverwhen the latter applies said force on said actuating member inopposition to said biasing means.

6. A holder as defined in claim 1, wherein said housing resembles asleeve having an open front end through which a portion of a tool isinsertable for engagement with said chuck means, said opening beingremote from said front end and having a polygonal outline.

7. A holder as defined in claim 6, wherein said opening is ofrectangular outline and has a width of approximately 3 mm. as consideredin the circumferential direction of said housing and a length ofapproximately 1.5 mm. as considered in the axial direction of saidhousing.

8. A holder as defined in claim 1, further comprising drive means havinga rotary output member received 6 in said housing and coupled to saidactuating member for rotation therewith, said actuating member beingmovable axially of said output member.

9. A holder as defined in claim 8, and wherein said biasing meanscomprises a helical spring surrounding said output member and operatingbetween said output member and said actuating member.

References Cited UNITED STATES PATENTS 462,530 11/1891 Booth 32-263,210,836 10/1956 Johanson et a1. 27951 XR ROBERT PESHOCK, PrimaryExaminer

